1. Field of Invention
This invention relates to a process for the production of polybenzimidazole microporous products. In particular this invention relates to a method for preparing catalysts which are bound into a microporous polybenzimidazole structure.
2. Prior Art
It is recognized that polybenzimidazoles in general, and aromatic polybenzimidazoles in particular, are characterized by a high degree of thermal and chemical stability. To utilize these advantages, polybenzimidazole polymers have been formed into many shaped articles including fibers, membranes, films and particulates. For example, polybenzimidazole fibers have been used to support catalysts useful in hydroformylation reactions. Examples of these catalysts include a rhodium carbonyl complex attached to a polybenzimidazole fiber support. See U.S. Pat. Nos. 4,066,705 and 4,077,906.
The particulate form of polybenzimidazole has been disclosed in U.S. Pat. Nos. 3,408,336, 3,560,158, 4,394,500 and 4,460,763. In addition, crosslinked bead copolymers of polybenzimidazole prepared by pearl copolymerization of 4-vinylpyridine, styrene, and divinylbenzene functionalized by reactions with various acids have been suggested for use as reagents in polymer supported chemical reactions and as acid scavengers in non-aqueous systems. (See Journal of Macromolecular Science--Chemistry, Vol. 11(3), pp. 515-534, (1977); and Journal of Organic Chemistry, Vol. 43, No. 13, pp. 2618-2621, (1978).
Recently, extensive research has been devoted to discovering compounds which are useful in absorbing or desorbing specific gases. In particular, various processes have also been disclosed for the manufacture of metal complexes capable of absorbing oxygen. For example, metal porphyrin complexes have been prepared which are oxygen absorbing and desorbing agents. See U.S. Pat. Nos. 4,104,466 and 4,530,794; J. P. Collman et al., Journal of the American Chemical Society, Vol. 97, pp. 1427-1439 (1975); and E. Hasegawa et al ., Bio-Chemical and Bio-Physical Research Communications, Vol. 105, p. 1416 (1982).
It is also well known that iron porphyrin complexes are useful as catalysts for oxidation of unactivated alkanes such as cyclohexane and cycloheptane. See Groves et al ., Journal of the American Chemical Society, Vol. 105, pp. 6243-48 (1983) and Tabushi et al., Journal of the American Chemical Society, Vol. 106, pp. 6871-72 (1984).
An additional metalloporphyrin catalyst is disclosed in W. Drenth, Journal of the Chemical Society, Chemical Communications, pp. 1204-1206 (1983) wherein a metalloporphyrin catalyst is anchored to a rigid polymer support for the enhancement of cyclohexene epoxidation reactions. The particular catalyst is a manganese porphyrin linked to a polyisocyanate polymer. However, the linkage of the porphyrin to the rigid polymer occurs through the phenyl groups on the porphyrin ring rather than through the metal. This linkage results in a less efficient epoxidation reaction than does the direct linkage with the metalloporphyrin metal.
In particular, there is no disclosure of the chemical binding of a metalloporphyrin to a polybenzimidazole article for use as a catalyst.
It is therefore an object of the invention to disclose a process for the chemical binding of metalloporphyrins to polybenzimidazole articles.
It is a further object of the invention to produce metalloporphyrin polybenzimidazole catalysts.
It is a still further object of the invention to disclose a process for the production of metalloporphyrin polybenzimidazole polymer beads useful as catalysts in epoxidation reactions.
These and other objects as well as the scope, nature and utilization of this invention will be apparent to those skilled in the art from the following detailed description and appended claims.